2 plump endives, trimmed
1 tart-sweet apple, such as Fuji or Gala
1 1/2 tablespoons salted butter (if you can find butter with sea salt crystals, use it)
4 small clusters white or green grapes
4 small rosemary sprigs
Salt, preferably fleur de sel, and freshly ground pepper
Cut the endives lengthwise in half. Cut the apple into quarters and remove the core. Peel off a thin strip of skin down the center of each quarter.
Put a large skillet over low heat and toss in the butter. When it's melted, put the endive into the pan cut side down and the apples skin side up. Add the grapes, scatter over the rosemary, and cook, undisturbed, for 20 minutes, at which point the underside of the endives will have caramelized and the apples and grapes will be soft and perhaps browned. Gently turn everything over, baste with any liquid in the pan, and cook for 20 minutes more.
Transfer the ingredients to a warm serving platter or to individual plates and using a sturdy wooden or silicone spoon, scrape up the cooking sugars sticking to the bottom of the pan. You might want to pour a few spoonfuls of water into the pan to help you nab the sugars and make a spare amount of sauce. Season the endive with salt and pepper, spoon over the jus, and serve. Serves 2 to